Study of Silicon-Germanium OxideNanostructure

• Main Authors: Keng-jen Chen, 陳鏗仁
• Other Authors: 高至誠
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/61257226264875020806

碩士 === 南台科技大學 === 光電工程系 === 98 === In this study, SixGeyO1-x-y films are grown by radio-frequency reactive magnetron sputtering using SiGe (50:50 wt.%) target. We analyze effects of controllable parameters on the film structure and properties. Si, Ge and O contents are extracted by X-ray photoelectron spectrometry (XPS). The SixGeyO1-x-y films are successively thermal annealed at 800 oC for 4h, and 900 oC for another 4h under N2 atmosphere. Transmission electronic microscopy (TEM) is used for observation of nano-particles. PL measurements are performed at room temperature under excitation at 325 nm of He-Cd laser. The results proved that radio-frequency reactive magnetron sputtering is promising for preparation of SixGeyO1-x-y films. During the deposition, introduction of oxygen gas (> 0.5sccm) leads to a high quantity of oxygen atoms in the chamber and then induces a film structure closed to SiO2. In addition, the film chemical structure is adjustable by controlling substrate temperature. When the substrate temperature is increased from RT to 200 oC, oxygen content decreases from 52 at.% down to 37.5 at.%, Si content increases from 39.3 at.% to 49.1 at.%, and Ge content increases from 8.7 at.% to 13.4 at.%. After thermal annealing, nano-crystals are formed in all the SixGeyO1-x-y films. For the films annealed at 900 oC, the grain size slightly increased and the diameter of largest crystal is about 10 nm. The annealed SixGeyO1-x-y films show strong PL with excitation at 325nm. The PL bands may be attributed to oxygen defects, surface state and the existence of nano-crystals. Our results suggest that the PL band centered at 510-580nm is most likely related to the nano-crystals indicating a potential application of SixGeyO1-x-y films in the emission filed and optical application.